diff --git a/sdk_container/src/third_party/coreos-overlay/sys-devel/gdb/gdb-11.2.ebuild b/sdk_container/src/third_party/coreos-overlay/sys-devel/gdb/gdb-11.2.ebuild
index a7deb85175..0130f4967b 100644
--- a/sdk_container/src/third_party/coreos-overlay/sys-devel/gdb/gdb-11.2.ebuild
+++ b/sdk_container/src/third_party/coreos-overlay/sys-devel/gdb/gdb-11.2.ebuild
@@ -154,6 +154,15 @@ src_configure() {
 		# Ideally we would like automagic-or-disabled here.
 		# But the check does not quite work on i686: bug #760926.
 		$(use_enable cet)
+
+		# Flatcar: we need to set both configure options, --with-sysroot
+		# and --libdir, to fix cross build issues that happen when
+		# configuring gmp. We explicitly need --libdir. Having only
+		# --with-sysroot without --libdir would not fix the build issues.
+		# For some reason, it is not enough to set only --with-sysroot,
+		# also not enough to pass --with-gmp-xxx options.
+		--with-sysroot="${ESYSROOT}"
+		--libdir="${ESYSROOT}/usr/$(get_libdir)"
 	)
 
 	local sysroot="${EPREFIX}/usr/${CTARGET}"